In Yvelines, you can climb to the top of this tower for a sweeping view of the medieval town.

Craving a bit of height? In the Yvelines, the town's centerpiece in Houdan is a massive donjon. Built between 1125 and 1132 under Amaury III, Count of Montfort, it once served to spot enemies and defend the town, and it remains the only surviving element. Though it has had many lives, imagine you can grimper à son sommet, thanks to a lengthy renovation in 2016, and enjoy a superb panorama over this ville médiévale.

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Centered on a tower 15 m in diameter and 25 m tall, it features four turrets. In the 16th century, the monument served as a prison, with executions carried out at the foot of the tower. In the 19th century, while many donjons médiévaux were being demolished, Houdan’s survived thanks to a stroke of genius. In 1880, instead of erecting an expensive modern structure, the decision was made to exploit the legendary durability of the walls of Amaury III de Montfort and convert it into a château d'eau.

A vast metal tank was installed, followed by a concrete cap at the very top of the tower, still visible. It’s fun to stand underneath, because the acoustics are unusually striking, with sound echoing like few places do. For more than a century, this historic landmark kept the pressure in the Houdanais taps and helped fight fires. It wasn’t until 1970 that it retired from hydraulic duty to become a pure heritage object once again, already listed as a historic monument in 1889.

You’ll come across a few inscriptions carved in stone—proof of life through the centuries and relics from times gone by. Before you reach the terrace, you can watch a short film that traces the keep’s history in the old cistern, now repurposed as a screening room.

To reach the panoramic terrace high atop the keep and take in the view, you’ll first ascend almost 250 steps, some dating back to the 12th century with varying widths and heights. The climb isn’t for everyone, but the lower chamber and its exhibitions are accessible to visitors with reduced mobility. Legend has it that on a clear day you might catch a glimpse of Chartres Cathedral!

Admission is 5 euros to take part in the visit, which is open to the public from March to October each year, weather permitting, on Wednesdays, Fridays and Saturdays.